The Brazilian has again attracted interest from the Liga side, but the Italian has told him to forget about leaving in January
Maurizio Sarri thinks it is "impossible" for Willian to leave Chelsea in January despite reports suggesting he could be part of a swap deal with Barcelona involving the out-of-favour Malcom.
Brazil international Willian was the subject of strong speculation in pre-season, with Barcelona reportedly having offers for him rejected.
In the end, Barca signed Malcom from Bordeaux to bolster their wide options, but the 21-year-old has hardly featured, playing just five times in La Liga.
Malcom cost Barca €41 million (£38m/$47m) and his slow start has seen a number of transfer and loan links crop up, with Everton originally thought to be front-runners before Marco Silva denied interest.
The latest rumours suggested Barca tabled an offer for Willian which amounted to €55m (£49m/$63m), including Malcom, but Sarri says the Chelsea man simply is not leaving.
When asked if he would be happy for Willian to leave, Sarri told reporters: "Of course not, because as you know a winger for us is very important.
"I think he can do better, because the potential is higher, but he's very important for us, so I think it's impossible to lose him in January.
"I didn't receive anything [about Willian] yesterday [Thursday]. You'll have to ask the club and ask about the market, because if you ask me about the market you put me in trouble, because I don't know."
Elaborating on his desire for Willian to play at a higher level, Sarri wants the winger to show more initiative off the ball and to make himself a bigger threat in the penalty area.
"Usually he wants ball to his feet, so I think he can improve in movements without the ball," Sarri said. "He has the potential to score more."
Alvaro Morata has also been heavily linked with a move away from Chelsea and is expected to depart in one way or another this month, with Sevilla interested in a loan deal and Atletico Madrid said to be considering signing him permanently.
If Morata does leave, Sarri will be insisting on a replacement.
"Of course, if he goes to another club we need a replacement, it's normal," the Italian added.
"At the moment, he is here, so I think he has to think only of playing, because in this moment in Europe there are another 300 players involved in the market and they must only think to next matches or it's impossible to play."
Cutberstyz
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Barcelona will be foolish to make this deal happen. Which team on earth will allow a young fresh blood like malcom to move to another team becoz of old dustbin like Willian, I no that this will never happen. Willian did not even have Barcelona pattern in him and he is even old. pls barca donot sign him becoz this player will not be able to play in the next four years to come but dembele and malcom will combine and be a greater forward for Barcelona for the next twelve years to come. I wish Barcelona board can see this and compare it to Madrid who did not see Ronaldo going this summer and replacing him with players that are not in the team for at least three years together for them to understand theirselves very well. pls barca donot do this deal pls ooo. Barcelona 4 live.